html,body,div,span,h1,a,ul,li,nav{
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  font: inherit;  /*字体设置，所有元素保持一致*/
  vertical-align: baseline; /*元素的基线与父元素的基线对齐*/
}
body{
  line-height: 1em;
  background-color: #f4f4f4;
  font-family: Arial,sans-serif;
  font-size: 14px;
  font-weight: lighter;    /*lighter 轻轻地*/
}
.l-main{
  width: 530px;
  margin: 0 auto;
}
.menu{
  width: 250px;
  margin: 40px;
  background: #fff;
  box-shadow: 0 1px 4px rgba(0,0,0,.3);
  border-radius: 5px;
  float: left;
}
.menu_header{
  background-color: #4b4f55;
  border-bottom: 1px solid #353a40;
  border-radius: 5px 5px 0 0 ;
}
.menu_header-title{
  color: #fff;
  padding: 15px;
  text-shadow: 0 1px 0 rgba(0,0,0,0.4);
}
.menu_body{
  border-radius: 0 0 5px 5px;
}
.nav{
  list-style: none;
}
.nav_item{
  position: relative;
}
.nav_item-link{
  padding: 10px 15px;
  text-decoration: none;
  color: #8b8e93;
  display: block;
  border-bottom: 1px solid #f0f0f0;
}
.nav_item-link:hover{
  background: #f0f0f0;
}
.nav_item-link.is-active{
  background: #6e757f;
  color: #fff;
  border-bottom-color: #4b4f55;
  box-shadow: 0 1px 0 #7a828d inset;   /*inset 内嵌效果*/
}
.nav_item-link.is-active:after{
  content: "";
  display: block;
  position: absolute;
  top: 50%;
  right: -6px;
  margin-top: -6px;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  border-left: 6px solid #6e757f;
}
.nav_item-link.is-active{
  color: #fff;
}
.nav_item:last-child .nav_item-link{
  border-bottom: none;
}
.nav_item-icon{
  width: 20px;
  text-align: center;
  font-size: 18px;
  margin-right: 10px;
}
.badge{
  font-size: 12px;
  padding: 2px 8px;
  border: 1px solid #d1d1d1;
  border-radius: 10px;
  position: absolute;
  top: 10px;
  right: 15px;
}
.badge-warning{
  background: #ed373f;
  border-color: #ed373f;
}
.fa-flag{
  color: red;
}
.fa-space-shuttle{
	color: green;
}
.fa-archive{
  color: orange;
}
.fa-envelope{
  color: #35b3ff;
}